Conventional personal navigation systems typically mirror automobile navigation systems but involve the use of a handset. However, traditional personal navigation systems usually rely upon static information that is located within a network server instead of the terminal itself, and navigation information is still accessed from a mass storage location. In such systems, a central server or other device is accessed in order to obtain information such as directions to a specific, static location. In recent years, systems have begun to locally use more dynamic information for various purposes For example, such systems have begun to use traffic congestion information that is received over radio.
One potential extension of this technology involves determining the location of another mobile user. It would be very beneficial to be able to determine another user's location, as well as to obtain directions to the person. However, such a system, if fully implemented, poses major privacy issues. Most individuals would not wish to allow the general public to know their precise location, and many people would prefer to control this information even for people with him they have a personal relationship.